<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <script src="https://cdn.bootcss.com/react/16.2.0/umd/react.development.js"></script>
    <script src="https://cdn.bootcss.com/react-dom/16.2.0/umd/react-dom.development.js"></script>
    <script src="https://cdn.bootcss.com/babel-standalone/6.26.0/babel.js"></script>
    <title>元素渲染</title>
</head>
<body>
<div id="root"></div>
<script src="demo2.js" type="text/babel"></script>
</body>
</html>